Automatic depth control for agricultural implements



W 9 1% w. H. SILVER AUTOMATIC DEPTH CONTROL FOR AGRICULTURAL IMPLEMENTS Filed June 19', 1941 INVENTQR I WALTER H. SILV Patented Aug. 6, 1946 AUTOMATIC DEPTHCONTROL FOR AGRICULTURAL IMPLEMENTS Walter H. Silver, Moline, 111., assignor to Deere & Company, Molina, 111., a corporation of Illinois Application June 19, 1941, Serial No. 398,781

14 Claims. (Cl. 97-50) The present invention relates generally to agricultural machines and more particularly to ground working implements in which ground working tools are provided.

The object and general nature of the present invention is the provision of depth controlling means deriving operating energy from the tractor engine and automatically responsive to changes in the depth of operation of the tool or tools, whereby substantially constant depth of operation maybe maintained automatically at any desired depth. More specifically, it is a feature of this invention to provide an implement having a movable ground engaging shoe or gauge member, movement of which relative to the implement automatically controls the application of power from the tractor to the depth adjusting mechanism so that if it should occur that the tool momentarily tend to run deeper or more shallow than the desired setting, the mechanism is operative to readjust the depth controlling means so as to momentarily readjust the depth of operation so as to bring the tools back to the desired position.

A further important feature of this invention is the provision of atomatic depth gauging mechanism which includes parts extending through or passing near the axis of relative movement between the implement and the tractor so that the source of power on the latter may be made effective to control the depth of operation of the implement but without in any way affecting the freedom of movement of the implement relative to the tractor which propels it. It is also a feature of this invention to utilize the depth controlling mechanism which also does not interfere with the freedom of movement of the tool or tools relative to the tractor.

These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawing which shows illustrative embodiments of this invention.

In the drawing:

Figure 1 is a side view of a tractor plow in which the tool means is connected with the tractor by a pair of vertically spaced links which pivot relative to the tractor so as to permit the tool means to float relative thereto, with means on the tractor for adjusting the operating depth and automatic gauge means responsive to changes in the operating depth for controlling the depth adjusting means;

2 this invention, incorporating a plowing implement in which the plow beam is connected with the tractor at a hitch point and is capable of relatively free floating movement relative to the tractor.

Referring first to Figure 1, which shows one form of the present invention, the reference numeral I indicates in it entirety a farm tractor having a motor 2 of conventional construction, the transmission housing of which is connected to a rear axle housing 3 carrying axle shafts 4 on which rear wheels 5 are fixed. The tractor I serves as a mobile support or supporting frame for ground working units of various kinds. A pair of brackets 8 are bolted, as at H, to the rear axle housing of the tractor and provide a support for a bell crank 9 which is preferably mounted on a pivot shaft I0 supported by the brackets B. Secured to the lower portion of the rear axle housing are a pair of draft angles I'2 between which the front end of a plow beam [3 is pivoted, the plow beam l3 preferably consisting of two forwardly diverging members similar to the lister plow shown in my co-pending application, Serial No. 314,821, filed January 20,

1940, now U. S. Patent 2,354,886, issued August 1, 1944. The rear end of the plow beam l3 curves downwardly and is pivoted, as at IE, to a furrow opener indicated in its entirety by the reference numeral l6. Preferably, the pivot I5 is formed at the lower end of a standard l8 that is fixedly secured to the frog of the furrow opener 16. A

Figure 2 is a side view of a modified form of 56 gauge wheel 20 is journaled on an axle 2] that 'is carried by a pair of brackets 22 suitably connected 'with the plow bottom or furrow opener l 6 and/or its standard 18. The upper end of the latter carries pivot means '25 on which a sleeve 26 is carried, and the latter adjustably receives the rear end of a link 28. The forward end of the latter is pivoted, as at 29, to one of the arms, indicated at 3|, that form the bell crank 9 mentioned above.

From the description so far it will be seen that the furrow opener IB is connected for relatively free floating vertical movement with respect to the tractor I since the members [3 and 28 are each pivotally connected to the tractor and to the standard I-8 at vertically spaced points. In this respect, therefore, the plow beam 13 serves as a link member cooperating with the link member 28 and the two link members serve generally as draft, means or hitch means for connecting the furrow opener l6 and its standard It to the tractor. Mechanismcf this kind for floatingly connecting a furrow opener to a tractor or other moves the lever 5| to its full line position (Figure 1), which shifts the valve 1I into a position ad- .mitting fluid to the rear side of the piston 6|,

, a counterclockwise direction relative to the plow beam I3. During such movement of the member 35 relative to'the plow beam I3, the connected .linkage also moves, including the arm 50, but

since the detent 52 is out of the notch 53, the movement of the arm 50 and associated parts now has no control of the valve 1I. Hence, as long as thehand lever 5| remains in the position shown in full lines. in Figure l, the plow I will be raised, It is desirable, however, to limit the upward movement of the tool, and to this end I mount a stop lug BI on the rear portion of the piston rod 62, and when the plow bottom I6 reaches its upper position, the lug 8| comes into contact with the arm I moving it to the rightand thus moving the valve 1I to a neutral or piston locking position.

When it is desired to lower the plow into an operating position, the operator moves the hand lever 5I forwardly, thus actuating the valve H and introducing pressure onto the forward side of the piston 6|, which forces the piston rod 62 rearwardly and lowers the plow. As the plow lowers, the ground engaging member 35 is first lowered into contact with the ground, and then subsequently moves in a clockwise direction relative to the plow beam and hence actuates the linkage. This motion continues until the corresponding movement of the arm 50, which is counterclockwise (Figure 1) when the plow bottom is lowering and the ground engaging element 35 moving in a clockwise direction relative thereto, brings the notch 53 into a position to be reengaged with the detent 52. When this occurs the hand lever 5| is then reconnected to the arm 50, and the next increment of movement of the latter acts through the arm 5| to move the valve 1I rearwardly from its forward or lowering position to its neutral or holding position. This terminates the lowering movement of the plow bottom so that subsequent operations take place with the bottom automatically controlled so as to be maintained at that depth. It will be noted that the hand lever 5| is actuable when it is desired to raise or lower the plow and that it is unnecessary to change the adjustment effected by the position of the adjusting lever 41.

- Reference above was made to the fact that .the pivot connection between the forward end of the link 39 and the arm 43, which is mounted on the tractor, is in substantial alignment with the pivot connection between the forward end of the plow beam I3 and the tractor carried angles I2. This is an important feature of the present invention, inasmuch as it permits the plow bottom I6, including the links I3 and 28, to move upwardly and downwardly as the tractor passes over irregularities in the ground surface without in any way interfering with the maintenance of the desired operating depth by the gauge shoe 35; in; other words, the plowbeam I3 can swing upwardly and downwardly about its pivotal connection with the angles I2, carrying with it the gauge shoe 35 without causing any change in the linkage between the arm 43 and the hydraulic unit 60. By virtue of this arrangement, I am enabled to carry the power actuating depth control on the tractor with the depth responsive gauging member on the implement while at the same time permitting the implement to have free vertical floating movement with respect to the tractor at all times, thus enabling the outfit to negotiate irregular terrain without in any way losing the advantages of automatic depth control.

Figure 2 shows another form of the present invention in which the depth responsive means serves automatically to maintain the plow bottom at the desired depth of operation. Referring now to Figure 2, the reference numeral IOI indicates a farm tractor of conventional construction.-

, neath the rear axle of the tractor IOI and has its forward end pivotally connected to a bell' crank, indicated in its entirety by the reference numeral H0. The latter is supported for rocking movement on a bracket II2 suitably fixed to the tractor, and one arm II3 of the bell crank I I0 extends rearwardly and pivotally receives the front end of the beam I01. The latter is therefore capable of rising and falling relative to the tractor by movement around the pivot axis H4. The bell crank III], and particularly the arm II3 thereof, serves as hitch means connecting the front end of the plow beam I01 with the tractor. A hydraulic power unit 50a, preferably identical for all practical purposes with the hydraulic unit 00 described above, includes a piston rod 62a which is connected by a link I I5 to the upper end of the arm II1 of the bell crank IIEI so that the latter may he rocked by the application of power from said hydraulic unit 50a. Rocking movement of the bell crank IIO thus serves to raise and lower th front end of the plow beam I01, causing the furrow opener I05 to operate at an increased or at a decreased depth of operation. The valve 1Ia controlling the operation of the hydraulic unit 50a is connected by means ofa link I2I to a, hand lever I22, the lower end of which is pivoted to an arm I23 which, like the arm 50 described above, is formed as a sector having a notch I24 with which detent mechanism on the hand lever I22 is adapted to engage so as to lock the hand lever I22 to the sector I23. This is the normal position of the hand lever I22 and is shown in Figure 2 in dotted lines. The lower end of the arm I23 is connected by a link I26 to a sector I21 which is pivoted, as at I28, to the plow beam I01. A ground engaging element I29 is also pivoted on the plow beam I01 at I28 and has its upper end formed with or carrying a hand lever I30 which is provided with detent mechanism I3I adapted to latch the lever I30, and the ground engaging element I29, to thc sector I 21. It will be noted that the forward pivotal connection of the link I26 with the arm I23 is disposed not far above the level of the pivot H4 and is generally adjacent the pivot connection between the forward end of the beam I 01 and the tractor, whereby when the plow beam I01 wings upwardly or downwardly there is relatively little pivoting of the sector I21 on its pivot I 28.

The gauge arm I29 operates to maintain the '-pl'ow l 06 at substantially a constant depth and =-in doing so functions approximately the-same as 1 the gaugeshoe-35 described above. Ifthe plow bettom l|l6-should tend-to rundeeper or more shallow than the depth that corresponds to set- --'ti-ngofthehand'lever- 1-30 on the sector I21, the 1 latter acts through the link 125,-the arm I 23, and the-lever i22,-which is normally latchedto the arm l23,- to canse the vawe Ha to readjust the hydraulic unit 60m to raise or lower the rear end i of th'e bell" crank arm" H3.

ln'order tolift the plow-"I06 to inoperative positiom meanssuchas-a-fleaiible cable 135 having "a rear secti'on i36, passingover'a -sheave I31 on the "tractor; connects-the upper-arm l l1'-of the 1 bellcrank'l mwith a bell crank I38-that is mounted for: rocking movement on the rear portion of 'lthe tractor. The beli crank 38 includesa rear arm' I 39-which is connected' by a normally slack chain I lll directlyto the plow beam Hi1.

W-hen-it desired to raise the plow into transport: position, the operator unlatches the hand lever l2 2' from-the notch- 124 and moves the lever 'l-il'from its'dotted line position '(Figure2) back to itsirfiill line position. This moves the valve 'lla in a position to cause the hydraulic unit 6011 'to force -thewpist'on fla forwardly. 'This first rocks'mhe beu' crank l'lfl in a' clockwise direction (Figure* '2); which hasthe eifect of causing the I pl'ow bottom 16' to momentarily operate at a :more shallow depth. 'As'ithe' forward movement --of thepiston 62a continues'the bell crank I38 is rooked in a clockwise direction I and eventually tightens the 'chaini-MPand lifts the plow bodily :intoiits transport position. The resulting counzter-clock'wise rocking of the depth adjusting gauge shoe 129 has no effect on the hydraulic ivalve mechanism since the hand lever I22 is disl-c'onne'cted from the arm 1'23. -=A- stop Mt of the :sector. 12! .serves to limit the counterclockwise movement of the gauge shoe l 29- when the plow :is' r'a'ised. Whenit is desired to lower the plow, :the operatormoves" the hand lever 122 forwardly, thus actu'ating the hydraulic valve mechanism to cause the 1 piston- 62a to be moved rearwardly, Qthus iie'rniitting:thebell crank I38 to rockin a counterclockwise direction-and lowerin theplow. The :lowering'movement thus; continues until the notch I24 reen'gages the detent mechanism of "the .hand lever: l'22, whereupon the next increment'of movement-shifts the hand lever I22 andmoves the :valve mechanism of -the hydraulic unit back 'into'fits' holding position. 'Ihis is substantially rthe samelaction as'd'es'cribed above in connection with Figure I andhas all of the advantages there- ;of, especially as regards being able I to raise and *lower the plowintoandout of its transport positiori- .without' losing the depth adjustment which iitzls :de'sired' that the gauge' shoe I 29* and associatedpa'rts shall automatically maintain.

While I have shown and-described above the :preferred means in which the principles of the present "invention? have been incorporated; it is -to'be.;understood that my invention 'is not to be limited .to the particular-"details shown anddescribed above; but that;' i1i" fact, w idely" difierent .means: mayrbe ..'emp'loyed the-practice bf 'the broader aspectsof my'inventicn.

What I claim, therefore;andde'siretoseciu'e by. LettersPatentis l. agricultural machine; comprising a pro- ..pelling unit,v.an implement including anioVable ground workingtool having suction and a forward point, means connectingsaidrimplementiwith said :propellingmeans to. accommodate tipping of the 8 tool and relatively free floating movement ofthe implement relative tosaid' propelling unit; gauging means movably connected with-'-said--implement and movable relative thereto-when the-operating depth or -..said tool varies, I controllable controllablemeansand.tip the point of said tool upwardly orf downwardly, respectively.

"2. An agriculturalimplement adapted:..-to; be connected with a .tractor having a SOHI-CGJ-Of power; said implement having a front end and comprising ground working. tool :means fixed thereto so that raising. or lowering'thefronttend of: said implement serves to adjust the operating position. ofthe toollmeans, movable draft means connecting. said implement with the tractoriand arranged toaccommodateat least verticalmovement of the front. end of said implement relative to. the tractor, means derivin operating :energy from such source. of power connected to said; mov- 30 able draft means for raising and. .loweringhthe front end of said implement so as to control the depth of operation of said tool means, means for controlling said raising .and lowering means, ground engaging gauge means-movably connected with said implement andtmovab'le relative thereto' in response to changesin the depth of operation of said tooltmeansgand' means connecting said gauge means with said controlling means for .operating. said raising and lowering. meansdby said-source. of power under the-control. of-said gauge means.

3. agricultural machine: adapted to beacon- .nected-with a tractor-having a-source of power, comprising ground working tool means, a pair or generally. vertically spaced draft members'con- .nected with said tool-means, .ground engaging gauge means-carriedlby and movable relative to said tool means in response'to changes in the-operating depth thereof,rmeans forishiftingone-oi said draft members to control .the depth of. operation of said tool-means; and means controlled by said. gauge means i oroperatively connecting said shifting means withsaid-source of power on the tractor for automatically -maintaining saidpto'ol r means at the desired depth of operation.

- 4. An agriculturalmachine adapted to be propelled by a tractor having a source of powen'comprising an implement unit, ground": working tool means .carriedby said implement, unit; bell crank .means for connecting said unit withv the" tractor for relatively free floating:movement,"movement of said bellcrank means in one-direction orithe otherservingto raise 'or' lower th front end of said .toolimeans a memher-pivoted'to said imple- .ment unitand extending downwardly and rear- -wardly ..therefrom in. generally trailingirelation,

ground engaging gauge '1 means carried: at the lloweriend-l of saidmember .to-fieffect movement thereof relative to. said implement :unit-iiin 'responsetochangesin the-operating depth of said tool means, controllable means/driven from said source of power for shifting saidbell1crank means :twvary the operating: depth: of .said .tool means while accommodating said relatively free' floating movement: ot the rimplement unit relative to the tractor, means for controlling said controllable and'exte'nding to andj'connected withsaid controlling means for actuating the controllabl bell crank Shifting means to maintain the desired depth of operation of said tool means in any position of said implement unit relative tojthe tractor by shifting said bell crankmeans.

5.- An agricultural machine comprising a tractor, a plow beam movably connected therewith at one end and having a furrow opener at the other end, controllable means on the tractor for raising and lowering said one end of the plow beam to control the depth of operation of said furrow opener, ground engaging gauge means movably connected with said plow beam and movable upwardly or downwardly relativ thereto in response to changes in the depth of operation of said furrow opener, means for operating said controllable means for raising and lowering the front end of said beam, and connections between said gauging means and the operating means of said controllable means for causing the latter to raise or lower the front end of the plow beam when said gauge means moves upwardly or downwardly relative to the plow beam.

6. In combination, a tractor, ground working tool means connected with the tractor for generally vertical movement relative thereto into and out of ground working position, means for adjusting the operating depth of said tool means, ground engaging means movably connected with said tool means, being movable relative to. the latter in response to changes in the depth of operation of said tool means, disconnectible means connecting said ground engaging means with said adjusting means, and means for disconnecting said disconnectible means.

'7. An agricultural implement comprising a ground working unit including tool means of the type having suction and tiltable at its front end in a generally vertical direction to cause the tool means to tend to run to a deeper or to a more shallow operating position, ground engaging means movably connected with said unit and movable relative to said tool means in response to changes in the operating depth thereof, controllable power operated means for changing the angular position of said tool means, means for controlling said controllable means, and means operatively connecting said ground engaging means with the controlling means of said power operated means for causing the latter to tilt the tool means and maintain substantially uniform penetration of said tool means.

8. An agricultural machine comprising a supporting frame, an implement including ground working tool means of the type having suction and tiltable in a generally vertical direction to cause the tool means to tend to run to a deeper or a more shallow operating position, hitch means connecting the implement with said supporting frame, ground engaging means carried by said implement and movable relative to said tool means in response to changes in the operating depth of the latter, and means controlled by said depth responsive means for adjusting the posi tion of said hitch means so as to maintain substantially uniform penetration of said tool means.

9. An agricultural machine comprising supporting means, an implement including ground working tool means of the type having suction and tiltable in a vertical longitudinal plane to cause the tool means to tend to run to a deeper or to a more shallow operating position and a pair of links connecting said tool means with said supporting means for generally vertical floating movement relative thereto, ground engaging means carried by said implement and movable relative to-said tool means in response to changes in the operating depth thereof, and means'controlledby said depth'responsive means for mov ing one of said links generally longitudinally for said controllable power operated unit means including disconnectible parts for connecting said movable means with said controlling means for operating the controllable power operated unit from said movable means, and means for disconnecting said parts so as to interrupt the connection between said position responsive means and said controlling means to provide for raising said tool means independently of said position responsive means.

11. An agricultural implement adapted to be I attached to a tractor having an implement-operating power unit and a control valve therefor, comprising a ground working too1 having suction and including a ground penetrating point, means for connecting the tool with the tractor for tilting movement in a generally vertical direction during operation, tilting of said ground working too-l serving to raise or lower the ground penetrating point of the tool so as to cause the tool to run deeper or more shallow, means adapted to be connected with said unit for tilting said tool in one direction or the other, a ground engaging member disposed adjacent and movable relative to said tool in response to changes in the I operating position of said tool, and operating means adapted to be connected between said ground engaging member and said control valve unit.

12. The invention set forth in claim 11, further characterized by a manual control incorporated in said operating means for controlling said valve unit independently of said ground engaging member.

13. An agricultural implement adapted to be attached to a tractor, comprising a generally longitudinally extending tool beam, a ground working tool having suction connected to the rear end of said tool beam, a bell crank adapted to be pivotally mounted on the tractor and connected with the front end of said tool beam, whereby rocking movement of said bell crank raises or lowers the front end of said tool beam, thereby tending to cause the tool to operate deeper or more shallow, means disposed adjacent and movable relative to said tool in response to changes in the depth of operation of said tool, controllable mechanism deriving operating energy from said tractor for shifting said bell crank, means for controlling said mechanism, and means connecting said depth responsive means with said controlling means whereby operation of said depth responsive means acts through said controlling means and said mechanism for raising or lowering the front end of said tool beam.

1 1 a 14.: In acombination; a :tractom gnoundr-workingtooL-means -.c0nnected:with -.thettractorzfor-,gepen allywertical movement relative thereto into -andoutzoil-groundworking= position,..-means:101': ad-

justingv-rthe :operating idepthmf said1.11001means";

gnound engaging (means movably. connected with.- 5 said 2 tool -means, being fimovablerelative .-;to the latter s.- in, .response r tor changes-31in: the depth of opgration of, saidJada-means, disconneetibte 

